In communication networks, it is known to utilize policy control functionalities for differentiating data traffic of a user, e.g., with respect to charging or Quality of Service (QoS).
For example, for mobile networks according of the 3rd Generation Partnership Project (3GPP), 3GPP Technical Specification (TS) 23.203 discloses a Policy and Charging Control (PCC) architecture for the Evolved 3GPP Packet System (EPS). This PCC architecture allows for example determining and subsequently enforcing policies for data flows relating to services involving a user equipment (UE) attached to the mobile network. These policies typically relate to charging or QoS. Also, it is possible to selectively authorize certain services or applications.
In this PCC architecture, a policy controller referred to as Policy and Charging Rules Function (PCRF) is utilized for making policy decisions with respect to services requested by the user of an UE. These policy decisions are then enforced by an entity referred to as Policy and Charging Enforcement Function (PCEF). Other nodes subject to policy control by the PCRF are entities referred to as Traffic Detection Function (TDF). Both the PCEF and the TDF are involved in routing signaling and/or media relating to said services. In this PCC architecture, the PCRF behaves as a Policy Decision Point (PDP) or policy server and for example stores user policies and determines which ones are to be applied. Nodes implementing PCEF and/or TDF functionalities actually route data flows to or from end users and behave as Policy Enforcing Points (PEP)s of the policies determined by the PCRF. A PCEF or TDF may for example be located in a gateway routing the data traffic.
The policy decisions made by the PCRF are transmitted, e.g., via interfaces referred to as Gx or Sd, to the PEPs that are involved in routing data flows conveying media and/or signaling of a service of a UE, e.g., in the form of PCC rules. Also, the PCRF can transmit to said policy enforcing point/s rules for detecting, policing and reporting usage by said UE of certain services; e.g., in the form of Application Detection and Control (ADC) rules.
Accordingly, the PCC architecture of 3GPP TS 23.203 allows for establishing policies with respect to data flow(s) relating to a service originated or terminated by an UE. These policies may be based on the specific service invoked or terminated by the UE, e.g., an Internet Protocol Multimedia System (IMS) session or a Hypertext Transfer Protocol (HTTP) web browsing session. The policies may also be based on a subscriber profile of the user.
However, the PCC architecture of 3GPP does not support differentiation between different types of content, e.g., to distinguish between different types of media content delivered by the same service.
A known concept for distinguishing between different types of content is referred to as content filtering, which is not merely based on the kind of accessed service as such, e.g., whether it is a HTTP based service or an IMS based service, nor merely on a network identifier of the server providing the service, e.g., Uniform Resource Locator (URL) of destination or origination, Internet Protocol (IP) address, or Transport Control Protocol (TCP) port. Rather, content filtering utilizes information about a content type or category, e.g., whether the content corresponds to an advertisement information type, adult information type, audio or video information type, certain file types, or the like. Such different content types or categories can be delivered within the same service. However, such content filtering techniques are not supported by known policy control architectures, e.g., the PCC architecture of 3GPP TS 23.203.
Accordingly, there is a need for techniques which allow for efficiently differentiating data traffic with a high degree of granularity, in particular on a content level.